Evaluating the potential of circular grass buffer strips to promote fungal community and soil health in water-limited agroecosystems

Buffer strip grasses enhanced microbial biomass by 37%, mainly the fungal responses.

Climate change has caused high weather variability, affecting crop production in arid and semi-arid regions. Circular buffer strips (CBS) of perennial native grasses can produce crops with less irrigation water while providing other ecological services. This study investigated the impact of CBS grasses on microbial abundances and soil health in water-limited semi-arid agroecosystems over five years (2017–2021). Experimental plots included corn (Zea mays L.) with and without buffer strips grass (BSG) in two adjoining center pivots. Soil samples were collected from 0–20, 20–40, 40–60, and 60–80 cm depths and analyzed for microbial community composition using phospholipid fatty acid (PLFA) indicators. Soils under BSG had greater biomass after the third year (37%), and this increase in microbial biomass was particularly mycorrhizal fungi. A significant decrease in microbial biomass with soil depths was also observed. Microbial biomass growth was strongly associated with annual precipitation, with water availability influencing the upper layers (0–20 and 20–40 cm) and soil nutrients, mainly nitrogen (NO ₃ ⁻ -N) and pH, affecting the deeper layers (40–60 and 60–80 cm). Incorporating BSG in cropping systems modifies soil microbial communities, primarily the fungal component while increasing soil health and boosting plant-soil microbial interactions.